Telephone system



H. H. IDE

TELEPHONE SYSTEM July 31, 1923'.

2 Sheets-Sheet 1 Filed July 28, 1919 Ig yv July 31, 1923 1,463,164

H. H. IDE

TELEPHONE SYSTEM Filed July 28 1919 2 Sheets-Sheet 2 airy 1570 2 Patented-Jewel, 1923.

"umrsn smrss PATENT -OFFICE;

HARRY n. IDE, or LA GRANGE, ILLINOIS, ASSIGNOR T KELLOGG swrrcnnonnnann SUPPLYCOMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS,

TELEPHONE SYSTEM.

Application filed July 28,-

TO all whom it may concern: I

Be it known that I, HARRY H. Inn, a (lltl zen of the-United States of America, resid-' ing in La Grange, county of Cook, and State of Illinois, have invented certain new and usefullmprovem'ents in Telephone Systems,

of which the following is a specification.

- Myinventionrelates to telephonesysterns of thetwo wire or 11161331110 llne type in which the 'directively' controlled switches at the exchangeare operated responsive toa series of rapid interruptions of the subscribers line circuits, and more particularly V magnets.

to a circuit arrangement adapted to operate in connection with switch. 3 I I A feature of my invention'is the provision of an automatic numerical or selector switch for use in an automatic telephone.sys' te mfwhich is providedwith only four op crating relays and the necessary operating a directively controlled further feature ofmy invention is the provision of a] combined impulse and testrelay. The relay, when its windings are serially connected, acts as an impulse I relay and receives impulses from the calling device at a calling substation to actuate means to step-the wipers of the switch in a pri mary direction to a desired group of contacts. When used as a test relay, after the termination of impulses, one winding, is connected in a local circuit with the'private test wiper through the contact of a second ary magnet for testingpurposes, and this arrangement I reduce the number of v relays required to actuate a switch.

The novel features of my invention through the provision of which the abovementioned and other advantageous results are obtained will' be explained by reference to the accompanying drawings in which.

' Parts 1 and 2 illustrate diagrammatically an automatic telephone system embodying my connected by means "of two line limbs, as

1919. Serial No. 313,799.

tiation of a. call-from the substation A to automatically connect with an idle first selector C as shownin Part l; The subscriber at A by the use of the calling device'GD in connection with the substation equipment may by its actuationgoperate' the first selector C to extend the connection from the said substation A to an idle connector switch D." The subscriber at A then may 1 by the. a

further actuation of his calling deviceGD. operate the connector switch-D to connect to the terminals of the called line E1. If the; called line E is idle,'ringing=current is an,-

' tomatical-ly applied to the terminalsithereof.

to signal the subscriber thereat. Should the line ofithe 'call'ed 'for subscriber be busy,= a'

characteristic busy signal will be rautomath cally transmitted back to-thecalling sub- 7 scriber who may byreplacing-his receiver upon its switch hook release the switches '7 which are used in extending his line Itoth'ev line dfrtheflca'l'led for-subscriber atsubsta.

tion

- The :switch line circuit,providedthe line iswitchaf-B is step over the .bank contactsfi, 6, and fTI. The

B 'is diagrammatically. .illu's' trated and comprises a double wound line,- and test relay LR, a single wound cut ofi re-f lay CO anda motor magnet MM. The line relayLR is adapted to" be energized overthe-two sides of the subscribers line. in se ries! The cut oii relay. CO is adapted when' ener'gized'to disconnect the :subscribers line, circuit .from the line relay LR "and to con-'- nect the'switch'wipersto the subscribers switch wipers :2, 3"and 4 are adapted toal ways .be. rotated in'the same direction and do not restore to normal, that is,;t-he';switch:

wipers do not have a normal positionbut remainin their antecedent progressive positlon when a vconnection 1s releasedi'iiThe' and as one contact end oflthesewipers'moves switch banks the other*conta'cting ends 7 thereof moveintoengagementwith the first i contacts oit' the switch banks. Thetofl' :nor-I mal contacts ON are so arranged that when the line relay LR is energized they are moved to their 5 normal position, and are returned to their normal position by-the energization of the cut oil relay CO. That is, these oil normal springs ON are so arranged that when the line relay LR is energized, the catch mechanism isoperated to release tne oil normal springs ON to their operated position and upon the energization of the cut oil relay CO, the springs are returned to their normal position in which position the catch mechanism is again brought into peration, to hold the oil normal springs ON in *their normal position.

The switch shaft which carries the wipers 2, 3 and 4 is provided with a ratchet mechanism which is adapted to co-operate with the driving pawl controlled by the motor magnet MM to rothen be energized to moveits switch con tacts to their alternate positions into engagement with their alternate contacts. Ti

the cut ofirelay CO is energized before'the line relay LB is operated, the armature of the cut oil relay CO is permitted to move only a suflicient distance that its contacts 8, 9 and 10 are moved from engagement with their back contacts 12, 13 and l grespe'ctively, but not into engagement with their frontcontacts 15, 16 and 17. This feature is provided so that when the substation A is called and the cut oil relay CO energized, the subscribers line is disconnected from the-line relay LR of the switch B, but cannot be connected with the switch wipers 2, 3 and i of the switch. The line switch B justdescribed is of the type shown in my co-pending application Serial No. 271,960 filed January 20, 1919-. The mechanical switch structure of line switches B and Bis of that type shown in my said copending. application SN.- 271,960. Said copending application shows the mechanical con-- struction of the switch and of the cut-off and line relays thereoi Reference is here made to said copending appl1cat1on for a more thorough understanding ofthe switch 7 structure of line switchesB and B.

The circuits for the selector switch C and connector switch D are adapted to work with a switch structuresimilar to that shown in my Patent Number 1402936, granted January 10, 1922.- I

The first selector C comprises a combined impulse and interrupter relay IR which renaesaea step the first selector switch wipers 18, 19

and 20 in a primary direction to a desired group of contacts. The secondary magnet SM is )IOVldQCl for the selector which ma net automatically steps the wipers 18, 19 and 20 in a secondary direction over the contacts 21, 22 and 23 in the selected group to seek an idle set of contacts leadingto a connector D. A switching relay T is also provided which when energized extends the connection of the calling substation A to the selected idle connector D. Primary off normal contacts PON are provided and assume their alternate position upon the first step of the wipers 18, 19 and 20 inia primary direction, and secondary off normal contacts SON are also provided'which assume their alternate position upon the first step of the said wipers in a secondary direction.

The connector switch l) is provided with an impulse relay IR responsive to the im pulses of the calling device CD of the call ing substation A, which relay TR brings about the actuation of the primary magnet PM to step the connector switch wipers 24, 25 and 26 in a pr mary direction to a certain group of contacts containing contacts of the called line E. I A switch relay SW is provided which energizes upon the termination of the first set of impulses to connect the secondary magnet SM in circuit with the impulse relay IE to be actuated by the energization and .de-energization thereof to step the connectorswitch wipers 24;, 25 and 26 over the contacts 27, 28 and 29 in the selected group to -the contacts of the called line E. A test relay TB is also provided which is actuated to test the busy or idle condition of the called subscribers line. The said test relay TR operates to connect the busy back apparatus BB to the calling subscribers line to notify the subscriber thereat oi the busy condition of the called line E. A ringing control relay RC is also provided for intermittently applying ringing cur rent to the called subscribers line from the ringing generator G. A supervisory relay SR is shown which operatesv upon the response of the called subscriber at substation E, and prevents the further applica tion of ringing current to the called line. Primary off normal contacts PON' and secondary off normal contacts SON are provided, which contacts assume their alternate position respectively upon the movement of the wipers 24;, 25 and 26 in their primary and secondary oil normal positions.

To the right of Part 2 I show a called substation E similar to the substation A, said substation E being connected to a line of the switches and apparatus I will now describe-more in detail the operation of the same.

Assuming that the subscriber at the sub-: station A initiates a call, the removal of the receiver by the subscriber at the substation brings about the energization of the line relay; LRof the line switch B, said circuit being traced from batterythrough the upperv winding of the line relay LR, normal contact of motor magnet MM, normal contact '31 of off normal contacts ON, normal contacts Hand 10 of cut off relay CO through the calling substation A back through contacts 8 and 12 of the cut off relay CO' and through the lower winding of the line relay LR to ground. Line relay LR upon energizing allows the oil normal contacts UN to move to their alternate or operative positions. K a

"As before mentioned,wipers 2, 3 and 4 always rest up'onthe set of contacts 5, 6 and 7 last used and assuming that the contacts upon whichthe-wipers now rest are/busy due tofanot'lier subscribers line switch having selected the first selector last used by the subscriber A, the private contact 5 will be connected to ground. v

The operation of the off normalcontacts ON connects the upper winding of line relay LE to the privatebank contact 5, and having, assumed thatthe private, contact 5. contains a busy potential, acircuit is established through the upper winding of the line relay LR tracedfrom battery through the upper winding of line relay LR, normal contact 30, of motor magnet MM, alternate contact 3110f off normal springs ON, contacts 13 and '9 of relay CO, conductor 32 to the private wiper 2 and the busy bank contact 5.' The line relay LR will thus remain energi zed'until its circuit is opened at normal 3 contact 30 of the motor magnet. MjM. Theclosure of alternate contact of line relay LR closes an energizing circuit forthe motor magnet MM traced from battery through the winding of the said magnet MM, alternatecontact 33 of relay LE to the private wiper 2,*and the grounded bank contact 5. The motor magnet MM upon energizing ;5- opens the; circuit of the line relay LR at its'contact 30 thereby permitting the said line relay LR to tie-energize. The motor magnet" MM at the same time steps the wipers 2, 3 and 4; to the next set of bank contacts 5,6 and '4'. "Relay LR restoring opens its alternate contact 33,v thereby open.- ing'the circuit of motor magnet MM and permitting the said motormagnet MM to restore. Should the contacts now engaged by the wipers 2, 3 and i be busy, the relay LR again energizes through normal contact 30 of motor magnetMM and the closing of alternate contact 33 o f "LR, again energizes.

motor magnet MM as above described. The

relay LR and motor magnet MM are thus alternatelyenergized and de energized, the magnet MM stepping the wipers 2, 3 and 4 from one set of contacts 5, 6 and 7 to the next as long as 'busy, that is, aslong as grounded contact-s 5 are encountered, and linerelay' LR energizes each time a grounded bank contact is engaged. Motor magnet MM opens and closes its contact 34 thus produ cing' a j vibratory circuit throughthe winding ofcut off 'relay'CO and contact 35 to ground. The winding of relay COisb'f high resistance and as the motor magnet MM energiz'esand de-e'nergizes with great rapidity, the said winding of the relay CO;

0s relayCO, said circuitbeing. traced-from battery through-the winding of relay normal contact 34 of the motor magnet MM,

alternate contact 35 of off normal contacts ON to ground.

a Relay CO upon energizing'restores" the off normal contacts ON,to='their normal positionand connects the subscribers; line 1 to theli-ne wipers 3 and 4t and connects'the windingof out oii'. relayCO to the private .1

wiper 2. The "relay C O beingvslow to re lease is held up momentarily until a subsititute circuit isestablished for the said relay GO as will be presently described. The

connection of the subscribers line tojthe line Wipers 3 andret of the switch B closes an energizing circuit for the combined impulse and interrupter relay IR,of the'firstf selector C; over a circuit traced ifrom battery through the" lower winding 2370f relaylR,

conductor 38, ni'ake-before-b-reak contact 39, conductor 40,'norma lly closed contact 11 of secondary ofl' normal contacts SON, conductor 4L2, normally ,closed'contact543 01? primary :otf normalcontact PON', conductor 4L4, normally closed contact 45' otthe' switching relay T, conductor 46, contact? ,7 wiper 4, contacts 10 and 17, of cut oil relay CO, throughthe substation A, back through contacts 8 and 15 of relay CO, wiper 3, contact 6, conductor fl, normal contact 48,}

of the relay T, conductor 49, to ground through the upper .winding '5O of the relay IR.

Relay 13 upon eleganc :noses. its

alternate contact 51, establishing an energizing circuit for the control primary relay (JR, traced from battery through the winding of the said relay CR, to ground at alternate contact 51 of relay 1R. The closure of alternate contact 52 of relay 1R establishes an energizing circuit for the relay 53 traced from battery through the winding of said relay 53, conductor 5a, normal contact 55 of primary off normal contacts PO'N, conductor 56, alternate contact 52 of relay IR, and conductor 57 to ground at alternate contact 58 of relayCR. The closing of alternate contact 67 of relay 53 establishes a substitute circuit for the interrupter relay IR traced from battery through the lower winding 37 ofrelay IR, conductor38, alternate contact 67, conductor a4, normal contact at, of the relay T and over the previously, described path to ground through the upper winding 50 of the relay TR. The

v primary ofi normal cont-act 4.3 assumes its alternate position upon the first step of the wipers ofi' normal and opens the initial energizing circuit of IE, but the substitute circuit just described for the relay IR holds the said relay TR energized to receive the remaining impulses that are sent from the calling device CD. The closing of alternate contact 59 of relay CR establishes a substitute holding circuit for the cut ofi relay 2, contact 5, conductors 60 and 61, to ground at alternate 001113210559 of relay GB. The cut ofi relay CO remains energized until time of release. 7

If the private contact 5 engaged by the wiper 2 is idle, when subscriber A initiates a call, the line relay LR is energized as before described and contacts ON assume their alternate position, but the closing of alternate contact 33 of relay LR does not energize magnet MM since there is no ground on contact 5 and motor magnet MM remains at normal. The cut oil relay CO; is immediately energized to ground at normal contact 35, and restores contacts ON as before described, and the out off relay CO is energized over the circuit to ground at the first selector C as already described. The switch B only travels when its wipers 2, 3-and 1 are in engagement with a busy set of contacts when a call is initiated by the subscriber at substation A.

An idle first selector C having been seized, as just described, and assuming that the number of the called substation E is 345, the subscriber A actuates the calling device CD to send three impulses of current over the line, which impulses bring about three rapio, ole-energizations and energizations of the impulse relay IR. The primary magnet normal contact 52 of relay IR. The circuit for magnet PM extends from battery through the winding of the said primary magnet PM, alternate contact 62 of relay 53, conductor 63, normal contact 52 of relay TR, and conductor 57 to ground at alternate contact 58 of relay CH. The magnet PM operates to step the wipers 18, 19 and 20 of the first selector U in a downward primary direction to the third group of contacts, thus selecting the three hundredth group of connectors.

. The primary olif normal contacts PON assume their alternate position upon the first step of the wipers 18, 19 and 20 oil" normal and the opening of normal contact 55 of primary oil normal contact PON opens the initial energizing circuit of the relay 53, but the relay 53 is held up from battery through the winding of the said relay 53, its alternate contact 64;, conductor 65, and alternate contact 66 of relay OR to ground at normal contact 51 01 relay IR, upon each de-energization of the said relay. Relays CR and 53 being slow-acting relays, are held in an energized condition during the rapid interruptions of the contact 51 of the relay IR. After the last impulse is sent the relay 53 restores to normal due to the continued energization of the relay IE, which relay now remains energized over a circuit traced from battery through the lower winding 37 there-- of, conductor 38, make-before-break contact 39 of relay 53, conductor 40, normal contact 11 of secondary ofi' normal contacts SON, conductor d2 to ground at alternate contact 41:3 or" the primary off normal contacts PON. The closing of normal contact 70 of relay 53 closes an energizing circuit for the secondary magnet SM, traced from battery through the winding of the said magnet, conductors 71 and 72, normal contact 70 of relay 53, alternate contact 55 of primary 05 normal contact PON, conductor 56, alternate Contact 52 of relay TR, to ground at alternate contact 58 of the control relay CR. The secondary magnet SM upon energization steps thewipers 18, 19 and 20 into engagement with the first set of contacts 21,22 and 23 of the selected group. Upon the first step of the wipers 18, 19 and 20 in a secondary direction, the secondary ofi normal contacts SON assume their alternate position opening the previously traced circuit through the lower winding of relay TR. Relay IR upon restoring, opens its altor'3, nornialcontact 73, of; magnet conductor T4, normal fcontactof switch-1 IR, upon energizationagain closes its alter nate contact 52 again'closing an "energizlng circuit for the secondary magnet SM The magnet SM and the relay IR are thus alternately energized and tie-energized to step operation of the magnet SM- issecur ed and the selector C will notstop ona husyi contact or pass an idle contact, because,'unless relay IR is energized, .magnet'SM cannothe energized and relay IR can only be energized when magnet SM is at normal and. private wiper 18. is resting on a'busy contact. The switching relayT does not energize during the secondaryn ovement ofthe Wipers due to its adjustment and the rapid interruptions of the contact 52 of the relay IR. The relay IR after the wipers .18, 19 and 20 "have engaged an idle set of contacts remains-at normal and the controlirelay QR, due to its slow release construction, is held. energized long enough to closean energizing. circuit for the switchina relay T' traced from hat a h, u 7,

'tery hrough the Winding of' the-sa id relay T, over conductor 78, normal Contact 62 of relay 5 3, conductor 63, normal contact of relay IR, and conductor 57 to ground at contact 58 of relay OBI "The closing ofalternate contact 79 of secondary ofi' normal con-s tacts SON places a substitute ground upon private conductor 60.

The c s g f t rnate 'cb e s 48 a 4-5 of relayT extends the connection of the calling subscriber-Jr to an lCllG, connector D engaged by Wipers 18, 19 and 20 ol'the first selector- C, bringing about the energization of the impulse relay TB" of theconnector switch. D over a circuit traced from ground through one winding of the said relay IR, contact 28, Wiper 20, alternate contact 15 of relay T, conductor 46,"contact 7, Wipert,

contacts 1.. and 1.0 o-lthe cut oft relay CO,

through the substation t -shack through .contactsS and 15 of relay C0, tylper 3, contact 6, conductor 17, alternate ,COntact 458 oi? relay T, n ipcr 19, contact='2 2, through the other of the impulsefrelay IR Oil co nctor D to hattery and ground.

-The restoration of the'control relay GB of the selector switch Census the initialen erg-icing circultoif'the relay of the seleo tor switch C but a locking circuit is estabing relay T,'Tcond uc tor 76 and wiper 18 to t e gr unded busy contact 21. The relay:

traced from: battery through 1 the winding I of the saidrelay, fits. alternate contact 7 5, conductor 76,wiper 18, contact 21, conductor 80-, and conductor '8lgto. ground at alternate con-'- IR of'connector SWltcliD; The said relay '1 remains energizedrntil conversation is terminated. 1

The energization of the "relay IR enerlished torf the" Swath clay I which maybe 70 tact 82 of the now energize-dimpulse relay I 7 5 s l y and 4:, the circuit or relay 83 extending from battery tliroughsthe right hand @ivinding of said relay, normal contactof the primaryoff-normal cont-acts EON/ conductor8 0 andconductor 81 to ground atalternate .contact82' of relay IR.- Relay-83 upon "energization, closes; a locking circuit for itself through its alternatecontact'89fto ground. Thecircuit for relay 84 extends from battery. through the -lower windin'g- "of 1 the relay 8 1,'conductors 86, 87 and alternate.

contact '88 to ground at alternate contact 82 of relay IR. Four impulses are now-transmitted from the calling device CD hy-the subscriber at substationA .Whiohfimpulses direction to. the fourth group of'contacts 90 d e-energize and; energize relay IR four times i A causing the primary niagnetBMQto energize and. des'energize four timesto step the ipers 24, 25 and26' in'a'downwa'rd primary .95 containing the cont-acts of the anea-1 mfi The circuit'of't'he primary magnet may be traced from battery through the'winding of the said inagnetPM, normal contact 90 of switching relay. .SVV, conductor 91, alterstep ofthe iswitchshaft, a ground is ted irom contact 93 of relay 94and substituted for the ground fed through contact 89' of e. frelay' 83. After the last impulse of thesethasheen sent, the steady-flow of current through both windings of relay '84 causes the isaid relay '84, due tofits diflerential action,

to. neutralize and restore its contacts-t0 normal, but it does notrestore during the-$en .1- ing ofimpulses, due to, ts ad ust1nent,c.on

struction and-the rapidity of theinterruptions of contact :88f The-closing of normal Contact 95. or' relay 84, energizes sw tchrelay SXV over arircuittraced from hattery through'fthe winding of said relay: SW,

its malre-hefore-breal contact' f 96," normal contact 97' ofsecondary, off-normal springs SON, conductor QS'fnOrrnal c ontact"" of relay 8 1-, and. conductor 99 toi'groundiatal-j ternate contactv 10,0 ofprimary 'off-norinali contacts EON,- aind-rela'y SVVflocks' itself to V. a e i c t-ec j Q fl and: lea-tre 61.08; .ing ot ialternatecontact 90 "of'the, sw tch ng 1..

100 'natecontact92 of rel-a-yf-8i, normalcontact 88-" of relay Iii, "conductor 81, conductor 80,

through normal contact 8'5-o-fthe; primary I .ofl. normal contact-s EON to ground at 'altei nate-contact89 ofrelay 83 ""After the pri-= mary ofifnor'mal contact 85- assu'mes-its alter- 'nate position Which I occurs upon the first r'u 'sw merely substitutes secondary mag:- 1

1 contacts 27, 28 and 29 ofthe called line. 'Upon the first impulse of the last set, the relay 84; again energizes to permit the secondary magnet SM to be operated, as previously described, and after the last impulse the .relay 84 is again die-energized, and closes a circuit for the test relay TR traced from battery, through the winding of the said relay, conductor 102, the alternate contact 103 remain energized but will de-energize.

of relay SW, alternate contact 97 of the secondary off normal contacts SON, (said contacts having been moved to their alternate position upon the first step 01? the wipers in their secondary direction), conductor 98, normal contact 95 and conductor 99 to ground at 100. The closing of alternate contact 104: of relay TR connects the said relay over conductor 105 to the test or private wiper 2 1, and should the called line be busy the private contact 27 of the called line would be grounded, thus closing a lock ing circuit for the said relay TR through the private wiper 24; to the grounded busy contacts 27.

Called line idle.

; Assuming that the called line is idle, pri

vate contact 27 of the called line will be free of ground, and the relay TR will not The upon itsimomentary energization opens the circuit ofthe switching relay Sl/V, and the relay S vV lo-energizing opens the clrcult of relay TR at its contact 103, leaving the relay TR dependent upon the potential found upon theprivate contact 27 of the called line. Since, as assumed, this contact is idle and thus free from ground, the relay T (lo-energizes and thereby causes the ener gization of relay 94: by current from battery,

through the winding 106 ol 'the cut-off relay C0 of switch B, conductor 107, contact 108, conductors 109 and 110, private contact 27, through wiper 2 1, conductor 105,

7 normal contact 1.04 of relay TR, conductor 112, normal contact 1130f relaySW, conductor 114, through the lower Winding of the relay 94, and conductor 115 toground at 116.

The closing of alternate contact 11 of relay 94 short circuits the lower winding ofthe said relay, and the closing iof its alternatecontact 118 closes a circuit through theupper wiuding'oi the said re- 7 lay throught'he alternate contact 118 and conductor "115 to ground at 116. -The relay nate contact 135 ltC disconnects the the called line E attracts, its armature but its movement is limited, as previously described, but this movement allows contacts 119 and 120 to assume positions to remove the substation control of the line switch B of the called line E. The other contacts of the relay C0 are not affected, due to this limited movement. 1

The closing of alternate contact 121 of relay 94 connects the interrupter I to the relay 122, over a circuit traced from battery through relay 122, conductor 123, alternate contact 121, of relay 94;, conductor 12a, normal contact 125 and through the interrupter I to ground. The relay 122 is thus intermittently energized and de-energized, and upon each de-energization ringing generator G is connected to the called line over a circuit extending from the ungrounded', pole of the generator G, through normal contact 126, of ringing control relay RC, conductor 127, alternate contact 128 of relay 9 1, conductor 129, normal contact 130 of relay 122, wiper 26, bank contact 29, through the condenser and call bell of the called substation back through bank contact28, wiper 25, normal contact 131 of relay 122, and conductor 132 to ground at alternate contact 93 of relay 9st. The call bell of the called subscriber at the substation E is thus intermittently rung, and when the called subscriber answers and the relay 122 is energized, a circuit for the relay SR is closed,- traced from battery through the lower winding of the relay SR, through alternate contact 130 of relay 122, wiper 26, contact 29, through the now closed upper contacts of the substation switch hook at thecalled substation E, back through contact 28, wiper 25, alternate con tact 131 of relay 122, and through the upper Winding of the relay SE to ground, The relay SR, upon energizing, closes an energizing circuit for the ringing control relay RC, which may be traced from batter through the winding of the said relay RC, its make-before-break contact 133, to ground at 13 1. Contact 135 looks relay RC over a circuit traced from battery, through the winding of the said relay RC, its alterand conductor 99 to ground at alternate contact 100 of the primary oft-normal contacts PON. The opening or normal. contacts and 126 of relay interrupter T and the ringing generator G to prevent further ap plica-tion of ringing current. .A substitute circuit :For the relay 122 is now established which may be traced from, battery, through the winding of the relay 122, conductor alternate contact 121 o'frelay'9-l, conductor 7 124;, alternate contact 125 of relay RC. and- .conductor 99 to ground at 100, The subscribers are now in conversational circuit.

and the talking circuit may be traced over the heavily marked conductors said conductorshaving the condensers K and K interposed.

' Release.

.6 Assuming that the. subscriber at the calling substation A is; the first to replace his receiver, the resulting'de-energization o-f'the impulse relay IR, of the connector D,.op.ens the'holdin circuitof the relay T of the firstselector C, and the closing of normal contact 140"of-relay'I- closes an energizing circuit for the secondary magnet SM traced trombattery, through the winding otma net SM, conductors 71* and 72, normal con tact 140 of relay T, conductor 141, vnorma l contact 142 of relay CR, conductor 143, normal contact 144 of relay SM,

conductor 145,? alternate contact 41 of secondary off-normal cont-acts. SONv and conductor"42 to ground at alternate contact- 43 of primary ofi' normal contacts PON. The secondary magnet SM is alternatelyenergized and de-energized, due to mal contacts SON opens the energizing eircuit of the cut-off relay C0 of the individual line switch' B. The restoration of the cut-ofi' relay CO restores the individual secondary magnet SM, 7 through said magnet, conductor 154, normal switch B to normal.

The subscriber E restoring his receiver upon its switch hook interrupts the circuit of the relay SR atthe switch hook contacts, causing the said relay to de-energize. The closing ofnormal contact 150 of relay SR- closes a circuit through the left hand win-ding of the relay 83 which circuit may be traced from battery, through" the left hand 'w-inding of the said relay 83', alternate contact 151, conductor 151', normal-contact 1500f relay SR, -and conductor 152 to ground at normal contact 82. Due to the difierential construction of relay 83, the

said relay neutralizes and restores to normal. The closing of normal contact 153 of relay 83 closes an energizing circuit for the from battery,

Contact 15$,contact 155, through the interr-upter ,-'I-to. ground. The secondary magnet- SM Ithus steps the wipersl24, '25 andQ o beyond the last set .ofcontacts in'thegroup,

and the wipers then restore to normal from this position by spring tension. The restoration-of the relay 83 opens'the circuit of'relay 94 at contact 116, and the relay 94 restoring opens the circuit of relay 122' at contact 121. 'The primary oft-normal contacts PON having restored fuponthe restorat-ion of the switch, the opening; of the relay 83 also brings aboutthede-energization of. the cuteofl relay GO oftheline circuit .B" which is. associatedwith the called sub scriber E. Y

All the apparatus used'in'establishing aconnection between a calling subscriber at7 at the substationEf is now .at normal and I available for use, in establishing-other conthe substation A'and the called subscriber nections. I 7

Assuming; now that the subscriber at the called substation E. was firstito jreplace his receiver upon the switch hooln'the opening contact de-energizes relayRC. Theofthe switch hook contacts at, the substation V E brings'about the de-energization of the relay SR.- Nothing else happens at this time as the relay IR'is still maintained energized overthe line of the calling substation A. The calling subscriber at the substation A replacing his receiver interrupts the circuit of I the impulse relayIR at the switch hook conhereinbeforedescribed. :The restoration of theindividual switch B, first selector. G and connector D is the same as previously described from this point on'. Should the called. subscriber E 't'ail to replace his -receiverupon-the switch hookeafter the conversation is terminated. the replacing of the receiver at the. substation A brings. about v the de-energization of the impulserelayIR of connector'D, the same as before, and the opening of alternate contact 82' ofcimpulse relay TR? opens) the circuit ofthe relay T of first selector C asbefore described, and causes the release of selector C and individual line switchB'.

The subscriber. at the called substation failing to replace his receiver, permits the continued energization of the relay SR, thus holding the contact 150 of said relaysin its alternate position preventing the diiterential Wound relay SS-trom restoring to normal, and closing the energizing circuit of the'secondary. magnetjSM. The relay S4 energizes when impulse relay IR drops back, but immediately restored to normal, duc'to the closure of an energizing circuit through the lower winding ot'the saidarclay 84, which :may;. be traced.- from battery,- through the said lower winding, jcondujctoi." 87, aiternate contact: :150 of relay SR; and,

conductor: to ground "at alternate *contact 82 cofrthe nowirestored impulse relay IR. Relayi84being d'iil'erentially wound,

restores to normal, and t-heiclosingot normal contact 160 of the said relay 84 places {a 7 ground upon the private contact of. the con necterD-over a circuit whijch may be traced from ground atcontact 100;, over conductor tacts. The relayIRde-energizing closesacin' cuit for the left hand winding of relay '83,

causing'the said relay to de-energize, as

contracts of a called subscribers line.

99, through normal contact 95 of relay 84, conductor 98, alternate contact 97, normal contact 160, alternate, contact 161 01 the secondary oil-normal contacts SON, to the private contact 21. Theplacing of this busy potential upon the private contact prevents any first selector switch 0 from selecting the contacts of this busy connector.

Called Zine busy,

' Assuming now that the called line is busy,

the operation of the circuit is the same up to and including the time that the relay TR momentarily energizes. The line being busy, the private contact 27 has a ground connected to it, and a locking circuit is thus closed for the test relay TH, traced iorm battery, through the Winding of the said relay, its alternate contact 104, conductor 105, and the wiper 24 to the grounded contact 27. Alternate contact 162 of the test relay TR remains closed and connects the busy signal BB to the calling line to transmit a busy signal to A, thus notifying the subscriber of the busy condition of the called substation E. Relay RC is also energized when connection is made toa busy line to prevent an application of ringing current being applied to the called line if the called line should become idle before the connector D is disconnected from the bank The relay RC'upon energizing locks up through its own IllilliG-bGfOIQ-blfilk contacts 133 and 135 to ground at alternate contact 100 1 The callin r subscriber now replaces his receiver, bringing about the de-energization of the impulse relay IR, and the relay IR restoring, opens the circuit of the relay T or" the first selector C, which, as'previously de scribed, brings about the release of the first selector C and the individual switch B. The relay IR de-energizing, restores relay 88 (since the relay SR has not been encrgized) and by the closing of circuit through the left hand winding of said relay 83, the closing of contact 153-now connects secondary magnet SM to interrupter l, and the connector restore to normal. 7 The primary oil-normal contacts FUN and secondary oil'- nornial contacts Stllfl are also restored, aul

etc; once parent d im- "ers llne circuit,'due to the fact that the two windings of this relay are connected in relay and test rela of suit. opeia lays.

series when so actuated andfthe windings are of the right resistance to operate most efliciently when its circuit is interrupted by the actuation of the: calling device at a calling substation, and when the relay is used for testing purposes, only its one winding is connected in circuit, which winding is of theright resistance to permit a. very ethcient operation of this relay under these conditions, thereby permitting the motor magnet of the switch to operate at a very high rate of speed. i

While I have described my invention op erating in connection with a well-known system, I do not wish to be limited'to this exact disclosure as my invention-may be applied to other systems without departing from the spirit of the invention, and T, therefore, do not wish to be limited to this exact disclosure, but aim to cover all such changes and modifications as come within the spirit and scope of the appended claims.

Having described my invention what I claim as new and desire to secure by United States Letters Patent is:

1. An automatic numerical selector switch. of the character described controlled over the two sides of the line in series, provided with only four operating relays, a pair 01" motor magnets, one ofsaid relays and one or said magnets being adapted .to be in vcluded in a vibratory circuit arrangement,

test means including said relay included in said vibratory circuit ior controlling the operating circuit of the other of said mag-' be included in a vibratory circuit arrange ment to oierate the said magnet to move the switch shaft in one dii-rection, test iii-cans including said relay included in said vibratory circuit :tor controlling the operating circuit of the other of said. magnets to move the switch in its other direction, and restoring means including said other magnet whereby said other magnet releases said switch to normal,

3. A two-dimension numerical automatic selector switch provided with a sw. .n shaft, operating magnets for moving said switch shaft, one of lsaid'magnets adapted to re store said switch to normal, awpair oi? slowrelays for saidswitch, switching .or said switch, and a combined line for controlling the opera tie-i ting magnets and ot said 4. A telephone system including a numcricalvselector S WltCll provided with a slow acting circuit changing relay, a line relay,

a circuit for said slow-acting relay adapted to-be closed upon the energizatior said line relay, oil-normal contacts adapted to be operated toopen circuit, anda oiidcircuit-ior said slow-acting relay .including one of itsowii contacts;

merical selector switch provided with aslowacting circuit changing: relay, a line relay, a circuit for said slowncting relay adapted to be closed upon the encrgization of said line "relay, off-normal contacts adapted to be operated to open thesaidcircuit, and a second circuit for said slow-acting relay including one of its own contacts and back contact of said line relay. c.

6. A system of the character described including asubscribers line, a selector switch for connection thereto provided with a pair of motor magnets, a line relay for COlll'iI0l ,ling one of said motor magnets, an initial energizing circuit for said line relayihcluding :saidsubscribers line, asecond circuit for said line relay including a contact of-tlie other of said motor magnets, a vcirciiitftor said lastinotor magnet including a contact of said line-relay, and means including said last motor magnet for restoring said selector switch to normal.

7. A selector switch of thecharacterdescribed provided with a switch shaft adapted to be'moved in two directions, motor mag nets for moving said switch shaft,"aline relay adapted to be intermittently operated to cause the operation'oi"? one of said motor magnets, circuit controlling means for connecting said line relay and the other of said motor magnets in a vibratorycircuit arrangement, and restoring means including one of said motor magnets for restoring said switch shaft."

8. A selector switch of the characterde scribed including a switch'shaitt adapted to be moved-in two directions, motor magnets for moving said'switch shaft, a line relay, a cir.-"

cuit for said line relay adaptedtoibe intermittently operated tocause the operation of one of said motor inagnets,.a circuit changing relayifor-opening the circuit of said line relay and for including said line relay in vibratory circuit arrangement with I the other. of saidrother magnets, and motordriven means for releasing said switch. v

9. A telephonev system including a numerical automatic switch provided with a contact maker, motor mechanisms for mov ing said contact maker, a double wound line relay for controlling one s of said motor mechanisms, aninitial energizing circuit for said relay includingthe two windings thereof in series, a second circuit for said line relay including one winding thereof and acontact controlled by the other part of said A" telephone system including a 1111- "D al. V 1 13. A numerical automatic selector switch motor mechanisms motor, mechanisms, a 'circuitfor said last motor mechanismincluding a contact "controlled by'said relay, and restoring'means including one of said motor mechanisms for restoring said contact maker.

lOLlA numerical selector switch of the character described includinga switch shaft, adapted to be moved in two diii'erent plane's, a pair of motor magnets for moving-said" switch shaftga line relay for controlling one of said motor magnets,ia localenergiz:

m circuit for said ,line'relayjincluding; a contact of the other of said magnets, 'a' c r" cuit for said other motor magnet includ ng a contact of'said line relay,and;'means includ ng said motor magnet for restoring said switch shatt to'normal,

11. A telephone system of the character.

described including "a subscribers' line, an

automatic selector switch provided" with fa switch, shaft adapted to be connected to said line, a line relay, for said selector switch controllable over. thetwo sides of said-line in series, [a motor magne'tcontrollable by i Y said; line relayffor' advancing saidswitch shaft, a second motor magnetlforjadvancing said switch shaft in a different plane,a local circuit for saidiline relay 'controlla'blefb'y said second motor magnet, and restoring means including said second motor magnet for restoring saidswitch shaft to normal.

? 12. 'A telephone system including a sub scribers teleghoneline, a numerical automatic selector switch'having motion in two different planes controllable oversaid line,

a line relay for said select'or'switch, a circuit therefor ncluding the two sides of said telephone line in ser1es,;alocaltest circuit in eluding awinding or saidlline' relay, a

pair of motor magnets for operating said switchin its two different planes, and re storing means including oneof said motor.

magnets for restoring saidswi tch to nor-[ onedirection to select a group oflcontacts and inanothcr direction :to select-acontact in the group, motor mechanism,, a line relay,- means for interrupting-the.circuit of said line relay to cause said motor mechanism to move the contact makerto a desired group of contacts, cther motor mechanism, other means for interrupting the circuit of said linerelay to cause the other motor mechanism to move the contact maker to an idle contact in the selected group of contacts, and restoring means including said other motor mechanism for restoring said contact maker.

15. An automatic numerical selector switch or" the character described provided with a contact maker adapted to be moved in one direction to selecta group of contacts and in another direction to select a contact in the group, motor mechanism, a line relay, means for interrupting the circuit of said line relay to cause said motor mechanism to move the contact maker to a desired group of contacts, othe' motor mechanism, other means for interrupting the circuit of said line relay to cause the other motor mechanism to move the contact maker to an idle contact in the selected group of contacts, a circuit changing relay for switching the line relay from one means to the other, and means including said other motor mechanism for restoring said contact maker to normal.

16. An automatic numerical selector switch of the character described provided with a contact maker adapted to be moved in one direction to select a group of contacts and in another direction'to select a contact in the group, motor mechanism, a line relay, means for interrupting the circuit of said line relay to cause said motor mechanism to move the contact maker to a desired group of contacts, other motor mechanism, other means for interrupting the circuit of said line relay to cause the other motor mechanism to move the contact maker to an idle contact in the selected group or contacts, a circuit changing relay for switching the line relay from one means to the other, and a switching relay for rendering the second of said interrupter circuits ineffective.

17(An automatic numerical selector switch of the characterdescribed provided with a contact maker adapted to be moved in one direction to select a group of contacts and another direction to select a contact in the group, motor mechanism, a line relay, means for interrupting the circuit of said line relay to cause said motor mechanism to move the contact maker to a desired group of conta ts, other motor mechanism, other means for interrupting the circuit of said line relay to cause the other motor mechanism to move the contact maker to an idle contact in the selected group of contacts, and means for again r,en dering said second motor mechanism etlective to restore said switch.

18. An automatic numerical selector neoaiee switch of the character described, a pair of motor magnets for said selector switch, a line relay, an interrupter for interrupting the circuit of said line relay thereby causing the said relay to operate one of said motor magnets, a second interrupter for operating said line relay to cause the same to operate the other or said motor magnets, and means for again operating one of said motor magnets for releasing said selector switch.

19. An automatic numerical selector switch or the character described, a pair of motor magnets for said selector. switch, a line relay, an interrupter for interupting the circuit of said line relay thereby causing the said relay to operate one of said motor magnets, asecond interrupter for operating said line relay to cause the same to operate the other of said motor magnets, a circuit changing relay for switching said line relay from one interrupter to the other, and means for advancing said switch to cause the restoration 01 said switch.

' 20.' in automatic num rical selector switch of the character described, provided with a line relay for controlling t roup selecting movement of said selector switch and for also controlling the contact selecting movement of said selector switch, and motordriven means for releasing said selector switch.

21. An automatic numeral selector switch of the character described provided with a movable contact. maker adapted to be moved to a group of contacts and then to an idle contact in the group, a line relay for controlling the first of said movements, a local circuit including a contac in said group of contacts for said line relay for controlling the second of said movements, and means for advancing said switch to cause the restoration of the same.

22. An automatic selector switch of the character described including a contact maker adapted to be moved to a desired group of contacts and then to an idle contact in the group, a combined line and test relay, an interrupter circuit for said line relay for controlling the first of said movements, a test circuit including a contact of said group of contacts for said line relay for controlling the second of said movements, and means for advancing said. switch to cause the restoration of the same.

An automatic selector switch of the character described including a contact maker adapted to be moved to a desired group of contacts and thento an idle contact in the group, a combined line and test relay, an interrupter circuit for said line relay for controlling the first or" said move ments, a test circuit for said line relay for controlling the second of said movements,

circuit changing relay for switching the line relay from one circuit to the other, and

'tion of said switch.

'means for advancing'said switch to its ultigroup'of contacts and then to an idle contact in the group, a combined line and test relay, an interrupter circuit for said line relay for controlling the first of said movements, a test circuit for said line relay for controlling the second of said movements, a

circuit changing relay for switching the line relay from one circuit to the other, and means for advancing the said selector switch to cause the release thereof.

25. In an automatic selector switch of the character described including a contact maker adapted to be moved to a group of contacts and then to an idle contact in the group, motor mechanism for producing the first of said movements, other motor mechanism for producing the second of said 'movements, a line relay, an interrupter circuit for said line relay for causing the intermittent operation of the same thereby causing the line relay to control the first of said motor mechanisms, a test means "for controlling said line relay thereby permitting the same to control the other of said motor mechanisms, and means including said other motor mechanism for restoring said switch to normal. v 26. An automatic. selector switch or" th character described provided with a contact maker adapted to be moved to a desired group of contacts and then to an idle contact in the desired group, a line relay and a slow-acting relay controlling the first of said movements, a second slow-acting relay, mechanism controlling the second of said movements controlled by said line relay and said second slow-acting relay, and means for advancing said contact maker to its ultimate rotary position whereby the same is restored to normal.

27. An automatic selector switch or" the character described provided with a contact maker adapted to be moved to a desired group of contacts and then to an idle contact in the desired group, a line relay and a slow-acting relay controlling the first of said movements, a second slow-acting relay, mechanism controlling the second of said movements controlled by said line relay and said second slow-acting relay, a switching relay for said automatic switch controlled by said line relay, and means for advancing said contact maker in its secondary direction to cause the restoration of the same.

28. An automatic selector switch of the character described provided with a contact maker adapted to be moved to a desired group of contacts and then to an idle contact in the desired group, a line relay and lease thereof.

"a slow-acting -r'elaycontrollingthe first of said 'movements, a-second slow-acting relay, 7 mechanism controlling. the second of said movements controlled by said line relay and said second slow-acting relay,-.a switching rel'ay for -said automatic-switch controlled by-saidilin'e relay, and m'ean-s for 'advan'cing 1 the said automatic switch to cause :the re- 29. An automatic numerical selector switch oi the character described having movable wipers, provided with only four operating relays, bank contacts, and with a pair of motor magnets, one of said motor magnets controlling the release of the switch, and one 03": said relays operating when energized to electricallyconnect said wipers to said bank contacts. V V i 30. A two-dimension numerical automatic selector switch having movable wipers provided with operating magnets for moving the switch shaft of said'iselector, a combined line and test relay, circuits controlled by said relay for controlling. said'magnets to step the said switch wipers in a primary and secondary direction, and means including one of said operating magnets to restore said switch shaft. V 1 31. A selector switch of the character described provided with a switch shaft adapted to be moved in two directions, motor magnets line relay adapted tobe intermittentlyoperated to cause the operation of one of said motor magnets, circuit controlling means for connecting said line relay and the other of said motor magnets in a vibratory circuit for moving said switch shaft, a

ico-

arrangement, and means operativetherear ter to render said last magnet effective to restore said switch.

p 32. An automatic selector switch provided? with a switch shaft, acombined impulse and. i,

test relay for controlling both the groupselecting movement of said switch shaft and the trunk selecting movement thereof, a 'lo' trunks during the trunking selection movement of said switch, and means for advancing said switch to causethe release 'ofsaid switch shaft. 1

33. An automatic selector switch o f the character described including 'motor .mag-

nets, a slow-acting relay for controlling the release of the switch, a slow-acting relay for I1 0 rendering one of said magnet stinoperative and for rendering the other operative, a com-' bined' line and test relay for controlling the 1 character described including motor mag'- nets, a slow-acting relay associatedwith one of said motor magnets for controlling the release of the switch, a slow-acting relay 11o, cal test circuitior said relay for testing the, V

for rendering one of said magnets inoperative and for rendering the other operative, a combined line and test relay for controlling themovements of said magnets, and a switching relay controlled by said line relay.

85.,An automatic selector switch having motion in two different planes provided with a test wiper, a line relay for controlling one movement of sand selector switch,

means for thereafter connecting said line re- 10 lay to said test Wiper for controlling the other motion of said switch, and means for advancing said switch to cause the release of the same.

Signed by me at Chicago, in the county of 

